Bilateral Anterior Interosseous Nerve Syndrome: A Case Report

Anterior interosseous nerve is purely a motor nerve and supplies flexor pollicis longus, flexor digitorum profundus to the index finger, and pronator quadratus. The etiology and treatment option of anterior interosseous nerve syndrome remain controversial. Bilateral involvement of the anterior interosseous nerve have been described rarely; however, we found no reported case of nonsimultaneous bilateral anterior interosseous nerve palsy associated with the entrapment neuropathy. We present the unique case of delayed anterior interosseous nerve syndrome, 3 years 5 months following an identical event in the opposite extremity and literature review.

Pseudo-Anterior Interosseous Nerve Syndrome by Multiple Intramuscular Injection

Blind intramuscular injection might cause severe neurovascular injury if it would be performed with insufficient knowledge of anatomy around the injection area. We report a case of pseudo-anterior interosseous syndrome caused by multiple intramuscular steroid injections around the antecubital area. The patient had weakness of the 1st to 3rd digits flexion with typical OK sign. Muscle atrophy was noted on the proximal medial forearm, and sensation was intact. The electrophysiologic studies showed anterior interosseous nerve compromise, accompanying with injury of the other muscles innervated by the median nerve proximal to anterior interosseous nerve. Magnetic resonance imaging of the left proximal forearm revealed abnormally increased signal intensity of the pronator teres, flexor carpi radialis, proximal portion of flexor digitorum superficialis, and flexor digitorum profundus innervated by the median nerve on the T2-weighted images. This case shows the importance of knowledge about anatomic structures in considering intramuscular injection.

The Anterior Interosseous Nerve Syndrome: Clinical Investigation of Surgically Treated 7 Cases

PURPOSE: The etiology and treatment strategy of the anterior interosseous nerve (AIN) syndrome are still controversial. Seven patients with the AIN syndrome who were treated by surgical exploration and neurolysis were reviewed at a mean of 35.9 months follow up period. MATERIALS & METHODS: There were six men and one woman. The mean age was 37.3 years, ranging from 26 to 59. No patient was related to trauma and associated neurological lesion. Surgical exploration was performed at 7.7 months after onset of paralysis. RESULTS: All except one patients experienced pain around the elbow region before the onset of the palsy. On 7 patients, only the flexor pollicis longus was paralysed in 1, only the index flexor digitorum profundus in 2, and none had paralysis of the middle. The most common compression structures were fibrous bands within flexor digitorum sublimis arcade. However there was no demonstrable abnormality in three. Recovery was complete in all cases within 12 months after surgery. CONCLUSION: We recommended surgical exploration and neurolysis in patients who have shown no improvement after 6 months of conservative treatment. And careful preoperative examination is essential to avoid misdiagnosis and inappropriate surgery, especially in incomplete AIN syndrome.

Anterior Interosseous Nerve Syndrome following Bowling: A case report

The anterior interosseous nerve is the largest branch of the median nerve. The anterior interosseous nerve syndrome is a rare focal neuropathy with typical clinical and electromyographic features. Most commonly reported etiologies include fracture of the forearm and arm, trauma or prolonged pressure on the forearm. A 26-year-old man was evaluated for weakness of the flexor pollicis longus, the second flexor digitorum profundus and the pronator quadratus muscles that occured following bowling. We report one case of anterior interosseous nerve syndrome following bowling, which was not related to trauma.